Copolymer Nanoparticles Research Articles

Poly(N-acryloyl glycinamide-co-N-acryloxysuccinimide) Nanoparticles: Tunable Thermo-Responsiveness and Improved Bio-Interfacial Adhesion for Cell Function Regulation.

Poly(N-acryloyl glycinamide) (PNAGA) can form high-strength hydrogen bonds (H-bonds) through the dual amide motifs in the side chain, allowing the polymer to exhibit gelation behavior and an upper critical solution temperature (UCST) property. These features make PNAGA a candidate platform for biomedical devices. However, most applications focused on PNAGA hydrogels, while few focused on PNAGA nanoparticles. Improving the UCST tunability and bio-interfacial adhesion of the PNAGA nanoparticles may expand their applications in biomedical fields. To address the issues, we established a reactive H-bond-type P(NAGA-co-NAS) copolymer via reversible addition-fragmentation chain transfer polymerization of NAGA and N-acryloxysuccinimide (NAS) monomers. The UCST behaviors and the bio-interfacial adhesion toward the proteins and cells along with the potential application of the copolymer nanoparticles were investigated in detail. Taking advantage of the enhanced H-bonding and reactivity, the copolymer exhibited a tunable UCST in a broad temperature range, showing thermo-reversible transition between nanoparticles (PNPs) and soluble chains; the PNPs efficiently bonded proteins into nano-biohybrids while keeping the secondary structure of the protein, and more importantly, they also exhibited good adhesion ability to the cell membrane and significantly inhibited cell-specific propagation. These features suggest broad prospects for the P(NAGA-co-NAS) nanoparticles in the fields of biosensors, protein delivery, cell surface decoration, and cell-specific function regulation.

Docking of COVID-19 main protease and TD-DFT/DMOl3 simulated method, synthesis, and characterization with hybrid nanocomposite thin films and its applications

Using the precipitation polymerization method copolymer poly methyl methacrylate co acrylonitrile was synthesized. Hybrid nanocomposite thin films [P(MMA-co-AN)/ZnO]HNC were prepared using the dip casting method by adding ZnO nanoparticles by the ratios 0.25, 0.20, 0.15, and 0.10 according to the weight of P(MMA-co-AN). Fourier Transform Infrared Spectroscopy (FTIR), UV–Vis optical properties, and laser photoluminescence PL characterization techniques were used to study [P(MMA-co-AN)/ZnO]HNC films. In addition, density functional theory (DFT), optimization via TD-DFTD/Mol3, and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP) were used to perform the geometrical study. FTIR spectra from [P(MMA-co-AN)/ZnO]HNC indicates the interaction between the copolymer and ZnO nanoparticles. In the wavelength range of 190 – 800 nm, the optical properties of [P(MMA-co-AN)/ZnO]HNC were considered. The direct energy band gap was found to be changed from 4.1 eV for P (MMA – co – AN) to 3.19 eV for 0.25 ZnO, while the concentration of 0.20 ZnO was the highest in the Urbach energy with 0.17 eV. The refractive index nλ=700 ranges from 1.48 to 1.81 for the concentration of 0.15 ZnO. Three emission peaks at 393 nm, 527 nm, and 775 nm were figured in the laser photoluminescence spectra of [P(MMA-co-AN)/ZnO]HNC films. In order to attain the restrained action of studied ligands (hybrid nanocomposite) novel coronavirus (COVID 19) main protest (6LU7) molecular docking studies were performed. The predicted energy gab by TD-DFT/DMOl3 was found to be agreed with the experimental data in a good manner.

Enhanced Adsorption of Epoxy‐Functional Nanoparticles onto Stainless Steel Significantly Reduces Friction in Tribological Studies

AbstractEpoxy‐functional sterically‐stabilized diblock copolymer nanoparticles (ca. 27 nm) are prepared via RAFT dispersion polymerization in mineral oil. Nanoparticle adsorption onto stainless steel is examined using a quartz crystal microbalance. Incorporating epoxy groups within the steric stabilizer chains results in a two‐fold increase in the adsorbed amount, Γ, at 20 °C (7.6 mg m−2) compared to epoxy‐core functional nanoparticles (3.7 mg m−2) or non‐functional nanoparticles (3.8 mg m−2). A larger difference in Γ is observed at 40 °C; this suggests chemical adsorption of the nanoparticles rather than merely physical adsorption. A remarkable near five‐fold increase in Γ is observed for ca. 50 nm epoxy‐functional nanoparticles compared to non‐functional nanoparticles (31.3 vs. 6.4 mg m−2, respectively). Tribological studies confirm that chemical adsorption of the latter epoxy‐functional nanoparticles leads to a significant reduction in friction between 60 °C and 120 °C.

Enhanced Adsorption of Epoxy-Functional Nanoparticles onto Stainless Steel Significantly Reduces Friction in Tribological Studies.

Epoxy-functional sterically-stabilized diblock copolymer nanoparticles (ca. 27 nm) are prepared via RAFT dispersion polymerization in mineral oil. Nanoparticle adsorption onto stainless steel is examined using a quartz crystal microbalance. Incorporating epoxy groups within the steric stabilizer chains results in a two-fold increase in the adsorbed amount, Γ, at 20 °C (7.6 mg m-2 ) compared to epoxy-core functional nanoparticles (3.7 mg m-2 ) or non-functional nanoparticles (3.8 mg m-2 ). A larger difference in Γ is observed at 40 °C; this suggests chemical adsorption of the nanoparticles rather than merely physical adsorption. A remarkable near five-fold increase in Γ is observed for ca. 50 nm epoxy-functional nanoparticles compared to non-functional nanoparticles (31.3 vs. 6.4 mg m-2 , respectively). Tribological studies confirm that chemical adsorption of the latter epoxy-functional nanoparticles leads to a significant reduction in friction between 60 °C and 120 °C.

All-in-one photoluminescent Janus nanoparticles for smart technologies: Organic light-emitting diodes, anticounterfeiting, and optical sensors

In this study, a new category of amphiphilic nanoparticles based on random copolymers was prepared by polymerization of the methyl methacrylate (MMA) with methacrylamide (MAAm) in emulsion media to develop functionalized nanoparticles containing amide polar groups in different concentrations, and also the size of nanoparticles is in the range of 47–145 nm. Subsequently, the physical modification of amide groups on the surface of functionalized amphiphilic nanoparticles by using oxazolidine derivative (OXOH) with a concentration of 5 wt% led to the development of photoluminescent copolymer nanoparticles (PLCNPs). The MAAm monomer was used to functionalize polymer nanoparticles with amide groups acting as electron donor groups for oxazolidine molecules and their stability on the surface of the polymer nanoparticles by hydrogen bonding. To investigate of optical properties, the PLCNPs samples containing different concentrations of amide groups (0–20 wt%) were studied by photoluminescence and UV–Vis spectroscopy. Obtained results indicate that the emission and absorbance bands (intensity and wavelength) can be influenced significantly by the concentration of amide groups located on the surface of amphiphilic nanoparticles, and most importantly the local polarity. Investigation of the color change of photoluminescence emission for PLCNPs samples as a function of amide group concentration by CIE colorimetric diagrams displayed regular shifts in color position by the increase of local polarity, which observed color shifts are in agreement with results of photoluminescence and UV–Vis spectra. It was observed that PLCNPs samples displayed suitable adhesion to the surface and stable optical properties when deposited or coated on substrates that have polar surfaces, such as thermoset/thermoplastic polymer sheets and also cellulose papers. Hence, the PLCNPs samples were used directly as the colloid solution to develop photoluminescence organic light emitting diodes, water-based and ecofriendly anticounterfeiting inks, and the portable sensor for the detection of artificially created scratches on the surface of the polycarbonate sheet by fluorescence imaging. The results displayed that printed security tags and encrypted information on cellulose papers have orange fluorescence emission with remarkable intensity because the size of latex particles is in the range of nanoscale (below 100 nm) which led to a reduction of light scattering and an increase of light absorption. In a new approach and for the first time, a solution of poly(vinyl alcohol) (PVA)/PLCNPs was deposited on LED (has blue light emission with a wavelength of 365 nm) to change the color of photoluminescence emission from blue to orange-purple by excitation of an organic photoluminescent polymer layer with UV light of LED (365 nm). On the other hand, the PLCNPs solutions were sprayed on the substrate to detect created scratches on the polycarbonate sheet under irradiation with UV light (365 nm) and fluorescence imaging. The advantages of developed water-based PLCNPs samples resulted in to use as an all-in-one nanomaterial in a different and wide range of applications, such as photoluminescent inks for ecofriendly anticounterfeiting technologies, photoluminescence OLEDs, and also a portable detector for optical visualization of scratches and micro-cracks on various substrates.

Dual-Color Photoluminescent Functionalized Nanoparticles for Static-Dynamic Anticounterfeiting and Encryption: First Collaboration of Spiropyran and Coumarin.

Increasing the security of anticounterfeiting materials has been the most important challenge in recent years, and the development of dual-color photoluminescent inks with multi-level security, static/dynamic emission, and dynamic color change is an important solution to overcome this problem. In this study, the multi-functionalized copolymer nanoparticles containing different functional groups (with a concentration of 20 wt %), including ester, carboxylic acid, hydroxyl, epoxide, amide, and amine groups were synthesized successfully by the emulsion polymerization method. The results showed that the particle size and morphology of nanoparticles are affected by the polarity of functional groups. The prepared multi-functionalized copolymer nanoparticles were modified physically with spiropyran (photochromic and red fluorescence emission) and coumarin (cyan emission) derivatives to develop dual-color photoluminescent polymer nanoparticles with application in static-dynamic photoluminescent anticounterfeiting inks, which have multi-level security. The investigation of optical properties indicates that the kinetics of photochromism and photoluminescence properties of samples containing spiropyran is dependent on the local polarity on the surface of polymer nanoparticles. Hence, an increase in the polarity (functionalization with amide, carboxylic acid, and hydroxyl groups) has resulted in fast photochromism, high-intensity photoluminescence emission and increased the efficiency of the photoswitchable color change of emission from cyan to pink. Dual-color photoluminescent anticounterfeiting inks were prepared by mixing polymer nanoparticles containing spiropyran with polymer nanoparticles containing coumarin, in different ratios (1:1, 1:3, 1:5, 1:8, and 1:10). Obtained results showed that prepared samples have cyan emission under UV light of 254 nm (static mode), and a dynamic photoswitching of fluorescence emission from cyan to pink (as a function of irradiation time) was also observed under UV-light irradiation of 365 nm, which is well known as a dynamic mode of emission. The responsivity and intensity of dynamic photoluminescence emission are dependent on the local polarity of the surface functional groups, in which the samples based on amide functionalized copolymer nanoparticles displayed high-intensity emission in the static mode and high-intensity photoswitchable dual-color emission in the dynamic mode, in the case of all ratios of colloid solution mixtures. Printing security tags on cellulose paper by dual-color photoluminescent inks indicates advantages such as maximum printability, resolution, brightness, and static-dynamic photoluminescence emission with high intensity for inks based on amide functionalized nanoparticles. The static-dynamic dual-color photoluminescent anticounterfeiting ink with unique properties and multi-level security was reported for the first time by the collaboration of spiropyran and coumarin. This study can open a new approach and window to the future of advanced and high-security anticounterfeiting technologies.

68Ga-labeled amphiphilic polymer nanoparticles for PET imaging of sentinel lymph node metastasis.

Precise diagnosis of lymph node metastasis is important for therapeutic regimen planning, prognosis analysis and probably better outcomes for cancer patients. In this work, 68Ga-labeled amphiphilic alternating copolymers nanoparticles with different rigid ligands were synthesized as positron emission tomography (PET) probes for lymph node metastasis imaging. The labeling efficiency and stability of nanoparticles was improved with increased rigidity of coordination unit. PU(68Ga-L-MDI-PEG) nanoparticles (PU(68Ga-L-MDI-PEG) NPs) with the strongest rigidity of coordination unit exhibited the lowest critical micelle concentration, the best 68Ga labeling efficiency and stability. During in vivo lymph node metastasis imaging, PU(68Ga-L-MDI-PEG) NPs led to different accumulations in normal lymph nodes (N-LN) and tumor metastasized sentinel lymph nodes (T-SLN), which resulted in different PET signal presentation, making it feasible to differentiate N-LN from T-SLN. In comparison, small molecule probe 68GaL had poor lymph node accumulation, not only making it difficult to find lymph nodes on PET/computed tomography scan, but also tough to distinguish N-LN from metastatic ones. Overall, this work provides a reference for design of 68Ga labeled polymeric nanoparticles with high chelation efficiency and stability, as sensitive PET probes for lymph node imaging.

Codelivery of dihydroartemisinin and chlorin e6 by copolymer nanoparticles enables boosting photodynamic therapy of breast cancer with low-power irradiation.

Given that chemotherapy as a stand-alone therapeutic strategy may not be sufficient to effectively treat cancer, there is increasing interest in combination of chemotherapy and alternative therapies. Photodynamic therapy has the advantages of high selectivity and low side effects, so the combination of photodynamic therapy and chemotherapy has become one of the most appealing strategies for tumor treatment. In this work, we constructed a nano drug codelivery system (PPDC) to realize the combined treatment of chemotherapy and photodynamic therapy through encapsulating chemotherapeutic drug dihydroartemisinin and photosensitizer chlorin e6 in PEG-PCL. The potentials, particle size and morphology of nanoparticles were characterized by dynamic light scattering and transmission electron microscopy. We also investigated the reactive oxygen species (ROS) generation and drug release ability. The antitumor effect in vitro was investigated by methylthiazolyldiphenyl-tetrazolium bromide assays and cell apoptosis experiments, and the potential cell death mechanisms were explored by ROS detection and Western blot analysis. The in vivo antitumor effect of PPDC was evaluated under the guidance of fluorescence imaging. Our work provides a potential antitumor treatment approach and expands the application of dihydroartemisinin for breast cancer therapy.

Nanocarrier of Pin1 inhibitor based on supercritical fluid technology inhibits cancer metastasis by blocking multiple signaling pathways.

Cancer metastasis is the primary cause of all cancer-related deaths due to the lack of effective targeted drugs that simultaneously block multiple signaling pathways that drive the dissemination and growth of cancer cells. The unique proline isomerase Pin1 activates numerous cancer pathways, but its role in cancer metastasis and the inhibitory efficacy of Pin1 inhibitors on cancer metastasis are unknown. Moreover, the applicability of Pin1 inhibitor-all-trans retinoic acid (ATRA) is limited due to its several drawbacks. Herein, uniform ATRA-loaded polylactic acid-polyethylene glycol block copolymer nanoparticles (ATRA-NPs) with high encapsulation efficiency, good cellular uptake, excellent controlled release performance and pharmacokinetics are developed using supercritical carbon dioxide processing combined with an optimized design. ATRA-NPs exhibited excellent biosafety and significant inhibition on the growth and metastasis of hepatocellular carcinoma. Pin1 played a key role in cancer metastasis and was the main target of ATRA-NPs. ATRA-NPs exerted their potent anti-metastatic effect by inhibiting Pin1 and then simultaneously blocking multiple signaling pathways and cancer epithelial-mesenchymal progression. Since ATRA-NPs could effectively couple the inhibition of cancer cell dissemination with cancer growth, it provided a novel therapeutic strategy for efficiently inhibiting cancer metastasis.

Nanoparticles of N-Vinylpyrrolidone Amphiphilic Copolymers and Pheophorbide a as Promising Photosensitizers for Photodynamic Therapy: Design, Properties and In Vitro Phototoxic Activity.

A series of nanoparticles (NPs) with a hydrodynamic radius from 20 to 100 nm in PBS was developed over the solubilization of hydrophobic dye methyl pheophorbide a (chlorin e6 derivative) by amphiphilic copolymers of N-vinylpyrrolidone with (di)methacrylates. Photophysical properties and biological activity of the NPs aqueous solution were studied. It was found that the dye encapsulated in the copolymers is in an aggregated state. However, its aggregation degree decreases sharply, and singlet oxygen quantum yield and the fluorescence signal increase upon the interaction of these NPs with model biological membranes-liposomes or components of a tissue homogenate. The phototoxic effect of NPs in HeLa cells exceeds by 1.5-2 times that of the reference dye chlorin e6 trisodium salt-one of the most effective photosensitizers used in clinical practice. It could be explained by the effective release of the hydrophobic photosensitizer from the NPs into biological structures. The demonstrated approach can be used not only for the encapsulation of hydrophobic photosensitizers for PDT but also for other drugs, and N-vinylpyrrolidone amphiphilic copolymers show promising potential as a modern platform for the design of targeted delivery vehicles.

Encapsulation of phenylacetic acid in block copolymer nanoparticles during polymerization induced self‐assembly

AbstractPolymerization induced self‐assembly (PISA) is an in situ method for producing block copolymer nanoparticles. Performing PISA in the presence of a pharmaceutical drug causes the nanoparticles to encapsulate the drug. While this approach is straightforward, the effects of drug loading and block copolymer composition remain unclear. Here, we investigate encapsulation of the drug phenylacetic acid (PA) in poly(glycerol monomethacrylate)‐block‐poly(2‐hydroxypropyl methacrylate) (PGMA‐PHPMA) nanoparticles during PISA. Nanoparticle morphology is characterized by electron microscopy and light scattering, while encapsulation efficiency () is quantified using nuclear magnetic resonance diffusometry. Increasing the PA loading shifts the nanoparticle morphology from spherical micelles cylindrical micelles vesicles. At a 32 mg/ml PA loading, maximizes at ~80%. Increasing the PHPMA degree of polymerization minimally impacts . The invariance of toward core block length suggests that PA binds to the nanoparticle corona, highlighting the importance of the hydrophilic block for drug encapsulation during PISA.

Histidine-Functionalized Diblock Copolymer Nanoparticles Exhibit Enhanced Adsorption onto Planar Stainless Steel.

RAFT aqueous emulsion polymerization of isopropylideneglycerol monomethacrylate (IPGMA) is used to prepare a series of PGEO5MA46 -PIPGMAy nanoparticles, where PGEO5MA is a hydrophilic methacrylic steric stabilizer block bearing pendent cis-diol groups. TEM studies confirm a spherical morphology while dynamic light scattering (DLS) analysis indicated that the z-average particle diameter can be adjusted by varying the target degree of polymerization for the core-forming PIPGMA block. Periodate oxidation is used to convert the cis-diol groups on PGEO5MA46 -PIPGMA500 and PGEO5MA46 -PIPGMA1000 nanoparticles into the analogous aldehyde-functionalized nanoparticles, which are then reacted with histidine via reductive amination. In each case, the extent of functionalization is more than 99% as determined by 1 HNMR spectroscopy. Aqueous electrophoresis studies indicate that such derivatization converts initially neutral nanoparticles into zwitterionic nanoparticles with an isoelectric point at pH 7. DLS studies confirm that such histidine-derivatized nanoparticles remain colloidally stable over a wide pH range. A quartz crystal microbalance is employed at 25°C to assess the adsorption of both the cis-diol- and histidine-functionalized nanoparticles onto planar stainless steel at pH 6. The histidine-bearing nanoparticles adsorb much more strongly than their cis-diol counterparts. For the highest adsorbed amount of 70.5mgm-2 , SEM indicates a fractional surface coverage of 0.23 for the adsorbed nanoparticles.

Lactate and glucose responsive boronic acid-substituted amphiphilic block copolymer nanoparticles of high aspect ratio

The establishment of conditions for formation of higher order morphologies (e.g. rods and worms) is important, as such nanoparticles are more efficient than spheres in drug delivery. Glucose-binding of core–shell nanoparticles comprising of boronic acid (BA) moieties occurs under basic conditions at above the pKa of the BA (pH 8.7). The resulting increased solubility of the core-forming BA-containing block is utilised in the delivery of therapeutics to diabetics. In contrast, the binding of the key anaerobic metabolite lactate to the BA moiety of amphiphilic block copolymers is unreported, despite occurring at lower physiological neutral pH 7.4. Herein, for the first time, high aspect ratio nanoparticles are observed for (unprotected) BA-substituted amphiphilic block copolymers in water, achieved by incorporating a non-stimuli responsive hydrophobic (tert-butylacrylamide) block. Amphiphilic diblock (Mn = 24,100 and 27,700 gmol−1) and triblock copolymers (Mn = 21,500 and 25,200 gmol−1) with relatively narrow molecular weight distributions (ᴆ = 1.31–1.48) were prepared by reversible addition-fragmentation chain transfer (RAFT) solution polymerizations. Aggregates formed upon dialysis with lactate at pH 7.4 were generally similar to those formed upon self-assembly with glucose at pH 8.7. Spherical nanoparticles for poly(N,N-dimethylacrylamide, DMA)28-b-(3-(acrylamidophenyl)boronic acid, 3-BAPhA)84-TTC (trithiocarbonate) decreased in size from Dh = 259 nm to mostly 100–150 nm upon ionization of BA-moieties with lactate, base, and glucose. Poly(DMA)96-b-(3-BAPhA)62 gave ∼ 500 nm long worms and lamellae under basic conditions, which transitioned to irregular spheres and rods upon addition of glucose. Self-assembly for triblock copolymers with BA-binding gave worms and fused spherical micelle rod-like structures.

Photoluminescent Janus oxazolidine nanoparticles for development of organic light-emitting diodes, anticounterfeiting, information encryption, and optical detection of scratch.

Photoluminescent polymer nanoparticles based on organic compounds are a new category of advanced materials with potential applications in various fields such as chemosensors, optical devices, drug-delivery systems, anticounterfeiting inks and bioimaging. Herein, amide functionalized copolymer nanoparticles with a particle size in the range of 42-139nm were synthesized by emulsion copolymerization of methylmathacrylate (MMA) and methacrylamide (MAAm) with different concentrations in the range of 0-20wt%. Afterward, the photoluminescent copolymer nanoparticles (PLCNPs) were prepared by physical modification of amide functionalized copolymer nanoparticles with 5wt% of oxazolidine derivative (OXOH). Investigation of optical properties include of photoluminescence and UV-vis spectra displayed significant dependency of emission and absorbance bands to the local polarity or the concentration of the amide groups on the surface of the nanoparticles. Study of Commission Internationale de l'Eclairage (CIE) colorimetric diagrams for PLCNPs samples confirmed the results of photoluminescence and UV-vis spectra, which a logical shift in color of the photoluminescence emission was observed by an increase in the concentration of the amide groups. The PLCNPs samples have remarkable stability (in physical and optical properties) when applied on polar substrates such as polymer sheet and cellulose paper. Therefore, the PLCNPs samples were used for development of eco-friendly water based anticounterfeiting inks, photoluminescence organic light emitting diodes (OLEDs), and also the photodetection of scratches in a fast and facile manner. The printed security tags and hand-written phrases on cellulosic papers have orange fluorescent emission with maximum intensity because nanoscale size of particles, which reduced the light scattering and increased the accessible concentration of OXOH for light absorption. A coating of poly(vinyl alcohol) (PVA)/PLCNPs solution onto a blue LED (365nm) was led to a change in the color of emission from blue to purple, because of the excitation of OXOH molecules at 365nm with the subsequent emission of purple light. The photodetection of created scratch on polycarbonate sheet was carried out by spray of PLCNPs solution on sheet and then illumination with UV irradiation (365nm). Developed water based PLCNPs samples have interesting optical properties, high stability on different surfaces and nanoscale particle size which are applicable in multiple applications such as eco-friendly photoluminescent inks for anticounterfeiting technologies, photoluminescence OLEDs, and also optical detector for monitoring of scratches on different substrates.

Synergistic effects of radiotherapy with JNK inhibitor-incorporated nanoparticle in an intracranial Lewis Lung Carcinoma Mouse Models.

Radiosurgery has been recognized as a reasonable treatment for metastatic brain tumors. Increasing the radiosensitivity and synergistic effects are possible ways to improve the therapeutic efficacy of specific regions of tumors. c-Jun-N-terminal kinase (JNK) signaling regulates H2AX phosphorylation to repair radiation-induced DNA breakage. We previously showed that blocking JNK signaling influenced radiosensitivity in vitro and in an in vivo mouse tumor model. Drugs can be incorporated into nanoparticles to produce a slow-release effect. This study assessed JNK radiosensitivity following the slow release of the JNK inhibitor SP600125 from a poly (DL-lactide-co-glycolide) (LGEsese) block copolymer in a brain tumor model. A LGEsese block copolymer was synthesized to fabricate SP600125-incorporated nanoparticles by nanoprecipitation and dialysis methods. The chemical structure of the LGEsese block copolymer was confirmed by 1H nuclear magnetic resonance (NMR) spectroscopy. The physicochemical and morphological properties were observed by transmission electron microscopy (TEM) imaging and measured with particle size analyzer. The blood-brain barrier (BBB) permeability to the JNK inhibitor was estimated by BBBflammaTM 440-dye-labeled SP600125. The effects of the JNK inhibitor were investigated using SP600125-incorporated nanoparticles and by optical bioluminescence, magnetic resonance imaging (MRI), and a survival assay in a mouse brain tumor model for Lewis lung cancer (LLC)-Fluc cells. DNA damage was estimated by histone γH2AX expression and apoptosis was assessed by the immunohistochemical examination of cleaved caspase 3. The SP600125-incorporated nanoparticles of the LGEsese block copolymer were spherical and released SP600125 continuously for 24h. The use of BBBflammaTM 440-dye-labeled SP600125 demonstrated the ability of SP600125 to cross the BBB. The blockade of JNK signaling with SP600125-incorporated nanoparticles significantly delayed mouse brain tumor growth and prolonged mouse survival after radiotherapy. γH2AX, which mediates DNA repair protein, was reduced and the apoptotic protein cleaved-caspase 3 was increased by the combination of radiation and SP600125-incorporated nanoparticles.

Single-ion nano-features formed by a Li-containing block copolymer synthesized via PISA

Synthesis of lithium-containing block copolymer nanoparticles via PISA and their use in the formation of structured thin films.

Stabilizing oil-oil interfaces with mixed-shell polymeric nanoparticles prepared via PISA and the grafting combination.

The preparation of mixed-shell polymeric nanoparticles (MSPNs) and their stabilized non-aqueous Pickering emulsions was described in this study. Poly(methyl methacrylate)-poly(4-vinylpyridine) (PMMA-P4VP) diblock copolymer nanoparticles with different morphologies including spheres, worms and vesicles were first prepared via reversible addition-fragmentation chain transfer-based polymerization induced self-assembly in toluene. C18 alkyl chains were subsequently grafted onto the surfaces of the as-prepared PMMA-P4VP nanoparticles, affording C18/PMMA-P4VP MSPNs with P4VP blocks as the core and C18/PMMA chains as the mixed shells. MSPNs were utilized as Pickering emulsifiers to prepare non-aqueous Pickering emulsions, where [Bmim][PF6] and toluene oils were selected. Two kinds of different Pickering emulsions, [Bmim][PF6]-in-toluene and toluene-in-[Bmim][PF6], could be formed, depending on the initial location of MSPNs. However, neither of them could be generated when PMMA-P4VP diblock copolymer nanoparticles were adopted as Pickering emulsifiers, indicating MSPNs were better than diblock copolymer nanoparticle precursors in the aspect of stabilizing oil-oil interfaces. The formation mechanisms of different kinds of Pickering emulsions were unraveled in this study.

Enhanced drug delivery to cancer cells through a pH-sensitive polycarbonate platform.

Polymer-drug conjugates are widely investigated to enhance the selectivity of therapeutic drugs to cancer cells, as well as increase circulation lifetime and solubility of poorly soluble drugs. In order to direct these structures selectively to cancer cells, targeting agents are often conjugated to the nanoparticle surface as a strategy to limit drug accumulation in non-cancerous cells and therefore reduce systemic toxicity. Here, we report a simple procedure to generate biodegradable polycarbonate graft copolymer nanoparticles that allows for highly efficient conjugation and intracellular release of S-(+)-camptothecin, a topoisomerase I inhibitor widely used in cancer therapy. The drug-polymer conjugate showed strong efficacy in inhibiting cell proliferation across a range of cancer cell lines over non-cancerous phenotypes, as a consequence of the increased intracellular accumulation and subsequent drug release specifically in cancer cells. The enhanced drug delivery towards cancer cells in vitro demonstrates the potential of this platform for selective treatments without the addition of targeting ligands.

Continuous synthesis of block copolymer nanoparticlesviatelescoped RAFT solution and dispersion polymerisation in a miniature CSTR cascade

Miniaturised continuous-flow reactors offer an economical and scalable route to explore the synthesis of block copolymersviaRAFT mediated polymerisation-induced self-assembly (PISA).

Preparation and characterization of cross-linked poly (vinyl alcohol-co-methyl methacrylate) colloidal nanoparticles from hydrolysis of poly (vinyl acetate-co-methyl methacrylate) as a promising cancer drug delivery system

Amphiphilic cross-linked poly (vinyl alcohol-methyl methacrylate) (PVA-PMMA) copolymer nanoparticles (NPs) were prepared using a two-step process. Unlike other polymers, which are typically produced via direct polymerization, PVA is produced from the hydrolysis of polyvinyl acetate (PVAc). Therefore, in the first part of the project, copolymeric PVAc-PMMA NPs were prepared by using the radical emulsion polymerization method in different concentrations of BDOD (0–10% mol.) and water: methanol compositions. Conversion degree, morphology, particle size, and polymerization rate of non-agglomerated samples were evaluated. The optimal sample that synthesized in water: methanol % (90:10) as polymerization medium and 2.5% mol. crosslinker was hydrolyzed by 0.6 M NaOH solution. To confirm the hydrolysis reaction, FE-SEM, FT-IR, DLS, 1H NMR, and TGA tests were performed. The optimal sample was loaded by methotrexate (MTX), and drug release investigated at different times by UV-vis spectrophotometry. The sustained and pH-responsive profile of drug release in vitro was observed, and 47.24% of the drug was released at pH = 7.4 and 65.39% at pH = 5.8 after 96 h. Also, the MTT assay and dual-fluorescent acridine orange/propidium iodide assay showed that drug-loaded nanocarriers exhibited anticancer activity as applied to MCF-7 cells.